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平面向量数量积的意义

> 已知两个单位向量 e1 ， e2 的夹角为θ，则下列结论不正确的是（　　） A． e1 在 e2 方向上的投影为cosθ B． e 21 = e 22 C．( e1 + e2 )⊥( e1 - e2 ) D． e1 • e2 =1

问题：

发布时间：2024-09-07

已知两个单位向量

e1

，

e2

的夹角为θ，则下列结论不正确的是（　　）

A．

e1

在

e2

方向上的投影为cosθ

B．

e

21

=

e

22

C．(

e1

+

e2

)⊥(

e1

-

e2

)

D．

e1

•

e2

=1

参考答案：

提问用户：lu***yz6

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已知两个单位向量 e1 ， e2 的夹角为θ，则下列结论不正确的是（ ） A． e1 在 e2 方向上的投影为cosθ B． e 21 = e 22 C．( e1 + e2 )⊥( e1 - e2 ) D． e1 • e2 =1

可能感兴趣的题目：

已知两个单位向量

e1

，

e2

的夹角为θ，则下列结论不正确的是（　　）

A．

e1

在

e2

方向上的投影为cosθ

B．

e

21

=

e

22

C．(

e1

+

e2

)⊥(

e1

-

e2

)

D．

e1

•

e2

=1